Interstate 15 lane closures that will reduce northbound travel from four to two lanes will take place over five weekends beginning Friday with significant delays anticipated.

Part of the $120 million Cajon Pass Rehabilitation Project that will extend the life of roadway surfaces about 40 years, the 65-hour closures are being called “The Cajon Crawl.” The duration will allow for a concrete curing time that provides a longer pavement life cycle compared to faster-curing cement pours, Caltrans said.

Lane reductions will allow for about a mile of paving each weekend, moving consecutively uphill from Highway 138 to Oak Hill Road.

The closures are scheduled to start at 10 p.m. Fridays starting this week and continuing Aug. 14 and 22, and Sept. 5 and 12. The closures will remain in effect until 3 p.m. the following Mondays, starting this week and continuing Aug. 18 and 25, and Sept. 8 and 15. Labor Day weekend will be skipped

Caltrans advises motorists to use alternate routes, adjust travel times or rideshare to help reduce traffic impacts and delays.

“One way (Victor Valley Transit Authority) is helping mitigate the increased traffic on the Cajon Pass is through its vanpool program, which lowers commuter costs to as little as $30 per week,” authority General Manager Kevin Kane said. “In May alone, the program’s commuter reduced single-occupancy vehicle miles a whopping 1.6 million miles. While this may not get you up the hill any faster, it does allow vanpool passengers to take a backseat to the stress of the traffic jams the High Desert has been experiencing.”

Shoulder access is limited throughout the project and commuters are asked to leave them clear for emergency vehicles.

A 60-mph speed limit will be strictly enforced by the California Highway Patrol.

CHP spokesman Johnie Russell said motorists should remember to slow down or move over for roadway workers and emergency personnel who are on the side of the road.

Infractions in construction zones are subject to double fines.

Gary Brodeur may be contacted at 760-951-6245 or gbrodeur@vvdailypress.com. Follow him on Twitter @DP_gbrodeur.